Headphones — Koss KEB25i

The Koss KEB25i is a noise-isolating stereo in-ear headphone built around an unusual layout. Placed outside the ear, its dynamic element feeds a tubular port that goes into a soft expandable foam cushion, which swells to fit the individual ear canal and improves isolation.

Key specs that matter

Koss quotes a 10 - 22,000 Hz frequency response, 16 ohm impedance and 111 dB SPL. A 1.2 m straight lead, dual entry, ends in a 3.5 mm plug, which keeps it compatible with phones, laptops and portable players.

Engineering and use context

A one-touch in-line microphone handles calls and voice commands, and the compact size suits commuting and travel. Black and white versions exist, and the model carries the Koss Limited Lifetime Warranty.